/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.runtime.heartbeat;

import org.apache.flink.configuration.Configuration;
import org.apache.flink.configuration.HeartbeatManagerOptions;
import org.apache.flink.runtime.clusterframework.types.ResourceID;
import org.apache.flink.util.Preconditions;
import org.apache.flink.util.concurrent.ScheduledExecutor;

import org.slf4j.Logger;

/**
 * HeartbeatServices gives access to all services needed for heartbeating. This includes the
 * creation of heartbeat receivers and heartbeat senders.
 */
public class HeartbeatServices {

    /** Heartbeat interval for the created services. */
    protected final long heartbeatInterval;

    /** Heartbeat timeout for the created services. */
    protected final long heartbeatTimeout;

    protected final int failedRpcRequestsUntilUnreachable;

    public HeartbeatServices(long heartbeatInterval, long heartbeatTimeout) {
        this(heartbeatInterval, heartbeatTimeout, -1);
    }

    public HeartbeatServices(
            long heartbeatInterval, long heartbeatTimeout, int failedRpcRequestsUntilUnreachable) {
        Preconditions.checkArgument(
                0L < heartbeatInterval, "The heartbeat interval must be larger than 0.");
        Preconditions.checkArgument(
                heartbeatInterval <= heartbeatTimeout,
                "The heartbeat timeout should be larger or equal than the heartbeat interval.");
        Preconditions.checkArgument(
                failedRpcRequestsUntilUnreachable > 0 || failedRpcRequestsUntilUnreachable == -1,
                "The number of failed heartbeat RPC requests has to be larger than 0 or -1 (deactivated).");

        this.heartbeatInterval = heartbeatInterval;
        this.heartbeatTimeout = heartbeatTimeout;
        this.failedRpcRequestsUntilUnreachable = failedRpcRequestsUntilUnreachable;
    }

    /**
     * Creates a heartbeat manager which does not actively send heartbeats.
     *
     * @param resourceId Resource Id which identifies the owner of the heartbeat manager
     * @param heartbeatListener Listener which will be notified upon heartbeat timeouts for
     *     registered targets
     * @param mainThreadExecutor Scheduled executor to be used for scheduling heartbeat timeouts
     * @param log Logger to be used for the logging
     * @param <I> Type of the incoming payload
     * @param <O> Type of the outgoing payload
     * @return A new HeartbeatManager instance
     */
    public <I, O> HeartbeatManager<I, O> createHeartbeatManager(
            ResourceID resourceId,
            HeartbeatListener<I, O> heartbeatListener,
            ScheduledExecutor mainThreadExecutor,
            Logger log) {

        return new HeartbeatManagerImpl<>(
                heartbeatTimeout,
                failedRpcRequestsUntilUnreachable,
                resourceId,
                heartbeatListener,
                mainThreadExecutor,
                log);
    }

    /**
     * Creates a heartbeat manager which actively sends heartbeats to monitoring targets.
     *
     * @param resourceId Resource Id which identifies the owner of the heartbeat manager
     * @param heartbeatListener Listener which will be notified upon heartbeat timeouts for
     *     registered targets
     * @param mainThreadExecutor Scheduled executor to be used for scheduling heartbeat timeouts and
     *     periodically send heartbeat requests
     * @param log Logger to be used for the logging
     * @param <I> Type of the incoming payload
     * @param <O> Type of the outgoing payload
     * @return A new HeartbeatManager instance which actively sends heartbeats
     */
    public <I, O> HeartbeatManager<I, O> createHeartbeatManagerSender(
            ResourceID resourceId,
            HeartbeatListener<I, O> heartbeatListener,
            ScheduledExecutor mainThreadExecutor,
            Logger log) {

        return new HeartbeatManagerSenderImpl<>(
                heartbeatInterval,
                heartbeatTimeout,
                failedRpcRequestsUntilUnreachable,
                resourceId,
                heartbeatListener,
                mainThreadExecutor,
                log);
    }

    /**
     * Creates an HeartbeatServices instance from a {@link Configuration}.
     *
     * @param configuration Configuration to be used for the HeartbeatServices creation
     * @return An HeartbeatServices instance created from the given configuration
     */
    public static HeartbeatServices fromConfiguration(Configuration configuration) {
        long heartbeatInterval = configuration.getLong(HeartbeatManagerOptions.HEARTBEAT_INTERVAL);

        long heartbeatTimeout = configuration.getLong(HeartbeatManagerOptions.HEARTBEAT_TIMEOUT);

        int failedRpcRequestsUntilUnreachable =
                configuration.get(HeartbeatManagerOptions.HEARTBEAT_RPC_FAILURE_THRESHOLD);

        return new HeartbeatServices(
                heartbeatInterval, heartbeatTimeout, failedRpcRequestsUntilUnreachable);
    }
}
